The statements in this section merely provide background information related to the present disclosure. Accordingly, such statements are not intended to constitute an admission of prior art.
Internal combustion engines utilize valve timing or phasing strategies to effect changes to engine operation and performance. Valve opening and closing timings influence the thermodynamic cycle and the combustion process, including fuel efficiency, emissions, and engine torque level.
A number of advanced combustion strategies are known. One strategy includes late intake valve closing (LIVC) spark ignition. Another includes homogeneous-charge compression ignition (HCCI). HCCI strategies are designed to improve the efficiency and emissions of the internal combustion engine, through a combination of reduced pumping work, an improved combustion process, and improved thermodynamics.